Telephone system.



. H. F. JOBOKEL.

' TELEPHONE SYSTEM.

-APPLIOATION FILED AUG. 10, 1911.

1,018,666. Patented Feh.2 7, 1912.

HENRY IE. JOECKEL, 0F CAMP POINT, ILLINOIS.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Application filed August 10, 1911.

Patented Feb. 27, 1912.

Serial No. 643,444.

To all whom it may concern:

Be it known that I, HENRY F. JOEOKEL, a citizen of the United States,residing at Camp Point, in the county of Adams and State of Illinois,have invented new and useful Improvements in Telephone Systems, of whichthe following is a specification, and which are illustrated in theaccompanying drawing, forming a part thereof.

The invention relates to a system similar to that disclosed in myapplication No. 614,964, filed Mar. 16, 1911,in which two line wires toform a metallic talking circuit are used, and the annunciators, of thesubstations of party lines, are connected to ground from each side ofthe metallic talking cirwit, the magneto circuit and central stationannunci'ator circuit being however wired differently.

The object is to provide means for a substation to signal the centralstation with-' out signalingthe substations upon the line and forsubstations to signal one another upon the line without signaling thecentral station. These objects are obtained in the mechanism and systemof wiring, as hereinafter described and shown in the accompanyingdrawing.

line jack 13 is connected at the tip spring a. to L and at the sleevespring 6 to L the annunciator 14; is normally bridged from L to L atline jack springs b, and a, by contacts 0, and d, respectively. Theinsertion of a switching plug into the line jack cuts the annunciatorout as usual, this adapts either line wire to be used separately by thecentral station for signaling the substations upon their respectivesides, a magneto 1 having one terminal grounded and the other terminalprovided with a switch p, to connect the magneto with L or L whichregister with L and L respectively whenever the switching plug isinserted into the line jack, is provided.

The telephone instruments of substation 22 consisting of a magneto 1, anannunciator 2, switch E, transmitter 3, receiver 4, induction coil 5,switch hook 7, condenser D, switch F, and their wiring are the same, asshown in my application No. 614,964, a contact m, has however been addedto the switch F, which is connected to wire j of binding post A, whichadapts the telephone set for this system. Suitable means are provided bya clip a, to disconnect the contact m, from wire f thus adapting thetelephone set to be used as the one of application No. 614,964. Thetelephone of substation 22 has binding posts A, B and O, and isconnected to L by binding post A, to L by binding post C and to theground by binding post B. The secondary talking circuit is from L to Lby binding post A, wire f, switch hook 7, wire f, induction coil 5, wiref condenser D, receiver 4, wire f, and binding post O, the circuit ishowever normally interrupted at the switch hook. The annunciator circuitis from L to ground by binding post A, wire f, clip 6, wire h,annunciator 2, wire it, switch E, wire f, and binding post B. Themagneto circuit to ground is simultaneously from L and L by the switchF, being from L by binding post A, wire f, clip a, contact m, switcharmF, magneto 1, wire h, switch E, wire f, binding post B, and from L bybinding post C, wire f, contact Z, switcharm F, magneto 1, wire 72/,switch E, wire f, and binding post B; and from L to L by binding post A,wire f, contact is, switcharm F, magneto 1, wire 71.", switch E, contact0, wire f, and binding post C, the magneto circuit is however normallyinterrupted at the usual cut out or at' a switch.

The telephone instruments and their wiring of substation 23, areduplicates of substation 22, the line connections of binding posts A,and C, are however transposed, binding post A, being connected to L andbinding post 0, to L the annunciator circuit being thus from L to groundat this station.

The metallic talking line circuit of L and L is nearly balanced bygiving each side of the circuit nearly an equal amount of ground, forthat purpose one substation annunciator is shown connected to groundfrom L and the other connected to ground from L all telephone lines ofthis system should have an even number of substations, and for lines offrom ten to twenty substations I recommend a resistance of 80 ohms forthe annunciator coil 14 at the central station, as the operating of theannunciator at the central station without disturbing those of thesubstations depends upon the coil at the central station takingsufficient of the signaling current generated so that the annunciatorsat the substations can not operate, from the current passing to groundthrough those of one side of the metallic circuit and back through thoseof the other side of the circuit, the resistance of the annunciatorcoils of the difierent stations, and the signaling current that can beused upon different lines of this system must therefore be suitablyproportioned.

This system furnishes selective signaling for two party lines as eachparty may signal the other without signaling the central station orsignal the central station without signaling the other party and thecentral station can signal either party without signaling the other bysignaling upon their respective side only.

The telephone instruments of substations 22 and 23 and their wiring,except the dividing of the talking and signaling circuits by the addingof switches E, and F, are those of telephones of the usual bridgingtelephone system, in which the bells have a resistance of from 1000 to2500 ohms, and by placing these switches in a position so the circuitscorrespond with the usual bridging system will fit these telephones alsoto be used upon said system, as well, as the adding of switches adaptthose telephone sets for this system. In two party lines of this systemthe heavy magnetos usually placed in bridging telephones are not needed.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The combination, in a telephone system, a central station, a metalliccircuit lead ing therefrom, and being normally closed at said station byan annunciator, a plurality of substation talking sets bridged into thesaid metallic circuit, said bridges being however normally interruptedat the switch hook, an annunciator at each substation connected toground from one or the other side of the metallic circuit so as to giveeach side of the metallic circuit nearly an equal amount of ground, amagneto in a normally open branch at each substation and means at eachsubstation to connect the magneto in circuit with the annunciator of thecentralstation or in circuit with all of the annunciators of thesubstations simultaneously upon both sides of the metallic circuit.

2. The combination, in a telephone system, a line jack at the centralstation, a metallic circuit leading therefrom, a plurality of substationtalking sets bridged into the metallic circuit said bridges beinghowever normally interrupted at the switch hook, a ground branch at eachsubstation containing an annunciator, connected to one or the other sideof the metallic circuit so as to give each side of the metallic circuitnearly an equal amount of ground, an annunciator at the central stationnormally bridged across the metallic circuit at the line jack, adaptedto be cut out whenever a switching plug is inserted into the line jack,a magneto in a normally open branch at each substation and means at eachsubstation to connect the magneto in circuit with the annunciator of thecentral station or in circuit with the annunciators of the substationssimultaneously upon both sides of the metallic circuit, a switching plugand means at the central station to signal separately upon either sideof the metallic circuit.

3. The combination, in a telephone system, a central station, a metalliccircuit leading therefrom, and being normally closed at said station byan annunciator, two substation talking sets bridged into the saidmetallic circuit, said bridges being however normally interrupted at theswitch hook, an annunciator at each substation connected to ground, onefrom one side of the metallic circuit the other from the other side ofthe metallic circuit, a magneto in a normally open branch at eachsubstation and means at each substation to selectively signal the othersubstation or the central station, and

means at the central station to signal either substation selectively.

4. The combination, in a telephone system, a central station, a metalliccircuit leading therefrom, and being normally closed at said station byan annunciator, two substation talking sets bridged into the said-metallic circuit, said bridges being however normally interrupted atthe switch hook, an annunciator at each substation normally connected toground, one from one side of the metallic circuit the other from theother side of the metallic circuit, a magneto. and means at eachsubstation to put the magneto in circuit with the annunciator of theother substation, with the annunciator of the central station or toleave the magneto out of circuit, the annunciators of said substationsbeing adapted to be operated selectively upon their respective sides bythe central station.

5. The combination, in a local battery magneto telephone, a secondarytalking circuitextendingfrom binding post A to C normally interrupted atthe switch book, In testimony whereof I have signed my an annunciatorcircuit normally extending name to this specification in the presence of10 from binding plost A to B, a magneto and two subscribing witnesses. vmeans to put t e magneto in a circuit ex- 7 tending from binding post Ato B, from HENRY JOECKEL' binding post A to G, or from binding postsWitnesses:

A and G to B, the magneto is however nor- JAMES R. MOFFETT,

mally not in circuit. e HENRY BARTLETT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

